diff options
Diffstat (limited to 'llvm/lib/Target/ARM/ARMISelLowering.cpp')
| -rw-r--r-- | llvm/lib/Target/ARM/ARMISelLowering.cpp | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/llvm/lib/Target/ARM/ARMISelLowering.cpp b/llvm/lib/Target/ARM/ARMISelLowering.cpp index 4349f291e50..e8cbada3447 100644 --- a/llvm/lib/Target/ARM/ARMISelLowering.cpp +++ b/llvm/lib/Target/ARM/ARMISelLowering.cpp @@ -1997,6 +1997,19 @@ ARMTargetLowering::IsEligibleForTailCallOptimization(SDValue Callee, if (Subtarget->isThumb1Only()) return false; + // Externally-defined functions with weak linkage should not be + // tail-called on ARM when the OS does not support dynamic + // pre-emption of symbols, as the AAELF spec requires normal calls + // to undefined weak functions to be replaced with a NOP or jump to the + // next instruction. The behaviour of branch instructions in this + // situation (as used for tail calls) is implementation-defined, so we + // cannot rely on the linker replacing the tail call with a return. + if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) { + const GlobalValue *GV = G->getGlobal(); + if (GV->hasExternalWeakLinkage()) + return false; + } + // If the calling conventions do not match, then we'd better make sure the // results are returned in the same way as what the caller expects. if (!CCMatch) { |
